There is a great need in agricultural and gardenproduce growing industries for grading different products according to their size, in a smooth and trouble-free fashion. Mechanical and electronic grading systems are known in the art. The mechanical systems cause damage to the products and do not result in uniform grading. The electronic systems sort the products singly in a channel or like conveyer, see for example, GB-A-1 571 889, U.S. Pat. No. 4,558,786, U.S. Pat. No. 1,722,751, U.S. Pat. No. 3,708,065, SU-749 456, SU-1 187 740, SU-749 456. Most of these systems are highly expensive in operation at normal capacity requirements. According to the present invention, the objects to be graded in accordance with their sizes are conveyed along a broad, flat conveyer path, and control informations based on image data taken by a camera and indicative of the size of respective objects is transmitted at the correct moment in time to groups of fingers which function to guide the objects in mutually different directions in accordance with their respective sizes. The invention enables a large number of objects to be sorted simultaneously from a conveyer path into mutually different, individually selective sizes. The method and apparatus proposed in accordance with the present invention are more gentle and more reliable in operation than methods and apparatus known hitherto, and are also much less expensive, since they provide a much greater grading capacity, such as 30 or more objects per second.
The invention will now be described in more detail with reference to the accompanying drawings, wherein: